Exhaust nozzle assembly for a turbojet engine

Abstract

An exhaust nozzle assembly for a turbojet engine is described wherein the position of a series of nozzle flaps is controlled by control levels interconnected with an actuating cylinder. The control levers are transversely interconnected in order to synchronize the movement of the flaps and to also permit variation in the transverse distance between adjacent control members. A linkage mechanism is also disclosed which permits the actuation of a second series of flaps from the interconnected control members.

What is claimed is: 
     
       1. In a turbojet engine having an annular exhaust gas outlet duct with a central longitudinal axis, the improved exhaust nozzle assembly comprising: (a) a plurality of hook members attached to the outlet duct and distributed evenly about the circumference of the outlet duct each hook member defining a generally "U" shaped slot extending across the width of the hook member, each generally "U" shaped slot having a first surface extending generally perpendicular to the central longitudinal axis and an adjacent second surface extending generally perpendicular to the first surface;   (b) a plurality of first nozzle flaps distributed about the circumference of the outlet duct;   (c) a journal shaft having two adjacent perpendicular surfaces, the length of the journal shaft exceeding the width of the hook members;   (d) attachment means to attach a journal shaft to each hook member such that the perpendicular surfaces on the shaft contact the first and second surfaces of the hook member slot;   (e) cylindrical bearing means on each end of the journal shaft;   (f) a plurality of control lever members operatively connected to selected nozzle flaps and pivotally attached to the cylindrical bearing means such that each control lever member pivots about an axis extending generally perpendicular to the central longitudinal axis;   (g) ball joint means interconnecting adjacent control lever members so as to synchronize the movement of the control lever members and to permit variation in the distance between adjacent control lever members as they pivot about their axes; and,   (h) a plurality of control cylinder means each having a stationary portion attached to the outlet duct and a movable portion attached to a control lever member such that the angle of the nozzle flaps with respect to the central longitudinal axis may be adjusted.   
     
     
       2. The improved exhaust nozzle assembly of claim 1 wherein each journal shaft defines a transverse threaded opening and the attachment means comprises: (a) a threaded bolt member extending through the hook member and threadingly engaging the threaded opening of the journal shaft; and,   (b) a tubular element interposed between the hook member and a head of the bolt member.   
     
     
       3. The improved exhaust nozzle assembly of claim 1 wherein the angle between the pivoting axes of adjacent control lever members taken in a plane transverse to the central longitudinal axis is approximately 360/N degrees, wherein N=total number of control lever members. 
     
     
       4. The improved nozzle assembly of claim 1 wherein the ball joint means comprises: (a) a female ball joint member attached to an end of a first control lever member;   (b) a male ball joint member attached to an end of a second, adjacent control lever member, the male and female ball joint members connected together so as to pivot about a pivot center located in a plane defined by the central longitudinal axis and a point of intersection of the pivot axes of the first and second control lever members.   
     
     
       5. The improved exhaust nozzle assembly of claim 4 wherein the female ball joint member comprises: (a) a female ball joint element;   (b) twin latches attached to the female ball joint element; and,   (c) means to pivotally attach the latches to an end of a control lever member.   
     
     
       6. The improved exhaust nozzle assembly of claim 5 wherein the male ball joint member comprises: (a) a mounting arm extending from an end of a control lever member; and,   (b) a male ball joint element attached to a distal end of the mounting arm.   
     
     
       7. The improved exhaust nozzle assembly of claim 4 wherein: (a) a plurality of first control lever members, each defining a generally radially extending groove at each end thereof, and wherein the female ball joint members are located within the grooves; and   (b) a plurality of second control lever members having a male ball joint member attached to each end thereof so as to engage the female ball joint members of the first control lever members disposed on either side of the second control lever members.   
     
     
       8. The improved exhaust nozzle assembly of claim 7 wherein each first control lever member comprises: (a) a transverse portion extending generally transversely of the central longitudinal axis, the ends of the transverse portion defining the radially extending grooves; and   (b) a pair of legs extending from a radially inward side of the transverse portion generally perpendicular thereto, the distal ends of the legs bearing against a corresponding first nozzle flap.   
     
     
       9. The improved exhaust nozzle assembly of claim 8 wherein each second control lever member comprises: (a) a transverse portion extending generally transversely of the central longitudinal axis; and,   (b) a pair of legs extending from a radially inward side of the transverse portion generally perpendicular thereto, the distal ends of the legs bearing against a corresponding first nozzle flap.   
     
     
       10. The improved exhaust nozzle assembly of claim 9 wherein each first and second control lever member further comprises a longitudinal arm extending from each leg, the distal end of each longitudinal arm bearing against a corresponding nozzle flap. 
     
     
       11. The improved exhaust nozzle assembly of claim 10 further comprising means to attach the distal end of each longitudinal arm to a corresponding nozzle flap. 
     
     
       12. The improved exhaust nozzle assembly of claim 10 wherein the movable portions of the control cylinder means are attached to the first control lever members. 
     
     
       13. The improved exhaust nozzle assembly of claim 10 wherein the movable portions of the control cylinder means are attached to the second control lever members. 
     
     
       14. The improved exhaust nozzle assembly of claim 4 wherein each control lever member defines a generally radially extending groove at a first end in which is mounted the female ball joint member and has means to attach the male ball joint member to a second, opposite end. 
     
     
       15. The improved exhaust nozzle assembly of claim 14 wherein the female ball joint member comprises: (a) a female ball joint element;   (b) twin latches attached to the female ball joint element; and,   (c) means to pivotally attach the latches to the control lever member.   
     
     
       16. The improved exhaust nozzle assembly of claim 15 wherein the male ball joint member comprises: (a) a mounting arm extending from the opposite end of the control lever member; and,   (b) a male ball joint element attached to a distal end of the mounting arm.   
     
     
       17. The improved exhaust nozzle assembly of claim 16 wherein each control lever member comprises: (a) a transverse portion extending generally transversely on the central longitudinal axis, the female ball joint member being mounted to one end of the transverse portion and the male ball joint member being mounted at an opposite end; and,   (b) a pair of legs extending from a radially inward side of the transverse portion generally perpendicular thereto, the distal ends of the legs bearing against a corresponding first nozzle flap.   
     
     
       18. The improved exhaust nozzle assembly of claim 17 wherein each control lever member further comprises a longitudinal arm extending from each leg, the distal end of each arm bearing against a corresponding nozzle flap. 
     
     
       19. The improved exhaust nozzle assembly of claim 18 further comprising means to attach the distal end of each longitudinal arm to a corresponding nozzle flap.